Leaf Footed Bug

Have you seen a large, brown bug walking around your walls and windowsills this fall? It probably is a leaf-footed bug. This nuisance insect invades homes in late summer and early fall looking for a warm crevice to spend the winter. They can fly but are most often seen walking on windows and walls. They do not injure houseplants or bite humans, though their large size and slow flight around the house can be startling.

There are several leaf-footed bugs that live in Connecticut. They are members of the Hemiptera, the true bug family, order Coreidae. Leaf-footed bugs get their name from the flattened, leaf like flare on the lower portion of the back legs or tibia. They are brown with white marks on the margins of their folded wings. They closely resemble an insect that vegetable gardeners are familiar with, the squash bug. The most important economically is the Western conifer seed bug (Leptoglossus occidentalis). A relatively new pest, it was first identified in Connecticut in 1985. They are relatively large bugs, getting to be one inch in length. Other leaf-footed bugs can be grayish to black.

Leaf-footed bugs feed on the flower, cones and seeds of many species. They are known to do damage to nut trees such as almond and pistachio. The conifer seed bug does most of its damage in conifer seedling operations. They have a long sucking mouthpart that pierces the flowers or fruit. This damage causes misshapen, unmarketable nuts.

Adults emerge in spring and feed on flowers and newly forming seeds. Soon they mate and lay eggs on host trees. The eggs hatch after about 10 days and the nymphs start feeding. There are five nymph stages, called instars before adulthood. It’s this nymph feeding that causes the most economic damage. They are adults by August and continue to feed through the fall. They overwinter as adults in protected areas including your house. There is only one generation per year.

Control of leaf-footed bugs is not necessary (unless you’re a pinecone grower!) They are easy to catch because of their slowing metabolism. Once caught, they can be tossed outdoors to find somewhere else to stay for the winter. Be advised, these are members of the stink bug family. If held too long or crushed they emit a foul odor.